[unreadable] Image artifacts arising from object motion represent one of the largest challenges for the development of diagnostic clinical instrumentation. Real-time correction of motion-induced image artifacts is especially important in the development of systems with spatial resolution greater than the average range of incremental motion and with acquisition speed less than the average velocity of the tissue under investigation. Although post-processing algorithms for the restoration of images corrupted by blur have been utilized for a number of years, these algorithms usually rely on assumptions gathered from the acquired image, and thus are inherently inaccurate and slow. Physical Sciences Inc. (PSI) proposes to develop a real-time motion correction system, based upon interferometry, which includes high-speed, high-resolution, hardware-controlled tracking of motion in three-dimensions. The real-time motion control system incorporates depth tracking into PSI's mature transverse tracking capabilities. A prototype system will be designed, built, and tested on tissue phantoms in the Phase I program. Depth and transverse tracking bandwidth will be characterized and compared to theoretical calculations for several experimental arrangements. After optimization, the Phase II instrument will be tested in a clinical ophthalmic program and the improvement in measurement of retinal features (e.g., nerve fiber layer thickness) will be quantified. [unreadable] [unreadable]